I claim the ornamental design for a garment hanger, as shown and described.
FIG. 1 is a front perspective view of a garment hanger in accordance with the new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken lines in the drawings illustrate portions of the garment hanger that form no part of the claimed design. The claimed design is not limited to the gray color shown in the drawings.